This invention relates to thermoplastic containers for pressurized liquids, and, more particularly, it concerns a plastic bottle for carbonated beverages, which is shaped to facilitate gripping by one hand.
To facilitate handling by one drinking a beverage from a bottle, it is known to provide glass bottles of generally cylindrical shape, with four peripheral finger grooves or recesses on one side of the bottle and a single thumb recess on the opposite side of the bottle. In bottles of relatively inflexible material, such as glass, the shape of the bottle has little or no effect on the ability of the bottle to stand upright, to withstand top loading forces during filling and when stacked for storage, or to withstand the pressure of the bottle contents without distortion of the bottle from its initial shape. However, when plastic materials are used in bottles for containing liquid beverages under pressure, the resiliency of the plastic container walls requires a generally symmetrical bottle configuration in order for the bottle to remain in its original configuration, both under top loading and under stress of internal pressure exerted by the bottle contents.
For example, if the known arrangement of finger grooves on one side of the glass bottle and a thumb indentation on the opposite side are incorporated in a bottle of thermoplastic material of normal material thicknesses, internal pressure tends to expand the side of the container in which the finger grooves are located, much in the manner of a bellows, so that there is a tendency for the bottle to bend on its vertical axis under the internal pressure. This bending reduces the ability of the bottle to be stacked and can reduce the ability to withstand top loading forces after being filled. The asymmetric shape also reduces the ability to withstand top loading forces prior to and during filling. In addition, asymmetric shape of a thermoplastic bottle containing fluid under pressure tends the distort the base of the bottle to a point where the bottle may not stand upright on a level surface.
With increased popularity of larger sized plastic bottles for beverages consumed during participation in sports and other recreational activities, there is a need for plastic bottles with a gripping facility resulting in bottle asymmetry giving rise to the aforementioned problems, and a solution of those problems.